Aufderheide E, Rink H, Hieber L, Kraft G
Int J Radiat Biol Relat Stud Phys Chem Med. 1987 May;51(5):779-90. doi: 10.1080/09553008714551071.
The relative biological effectiveness (RBE) for the induction of DNA strand breaks and the efficiency of repair of these breaks in cultured diploid bovine lens epithelial cells was measured, using accelerated heavy ions in the linear energy transfer (LET)-range up to 16,200 keV/micron. At LET values above 800 keV/micron, the number of DNA strand breaks induced per particle increases both with the atomic number of the projectile and with its kinetic energy. About 90 per cent or more of the strand breaks induced by ions with an LET of less than 10,000 keV/micron are repaired within 24 h. Repair kinetics show a dependence on the particle fluence (irradiation dose). At higher particle fluences a higher proportion of non-rejoined breaks is found, even after prolonged periods of incubation. At any LET value, repair is much slower after heavy-ion exposure than after X-irradiation. This is especially true for low energetic particles with a very high local density of energy deposition within the particle track. At the highest LET value (16,200 keV/micron), no significant repair is observed.
利用线性能量转移（LET）高达16,200 keV/微米的加速重离子，测量了培养的二倍体牛晶状体上皮细胞中DNA链断裂诱导的相对生物学效应（RBE）以及这些断裂的修复效率。在LET值高于800 keV/微米时，每个粒子诱导的DNA链断裂数量随射弹的原子序数及其动能而增加。LET小于10,000 keV/微米的离子诱导的链断裂中，约90%或更多在24小时内得到修复。修复动力学显示出对粒子注量（辐照剂量）的依赖性。在较高的粒子注量下，即使经过长时间孵育，未重新连接的断裂比例也更高。在任何LET值下，重离子照射后的修复都比X射线照射后慢得多。对于在粒子径迹内具有非常高的局部能量沉积密度的低能粒子尤其如此。在最高LET值（16,200 keV/微米）下，未观察到明显的修复。
